A puppy weighs 2.0 lbs at birth and 3.5 lbs two months later. If the weight of the puppy during its first 6 months is increasing at a rate of proportional to its weight, then how much will the puppy weigh when it is 3 months old?
Steps please!
2007-04-20 08:07:09 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
The statement in math terms"
dw/dt = k w, t in months.
dw/w = k dt
ln w = kt
w = exp(kt)+ const
we have two unknowns, k and the constant.
we have two known points on the function curve,
at t=0: 2 = 1 +const, => const=1
at t=2: 3.5 = exp(2k)+1
2.5= exp(2k)
0.9 = 2k (approx)
k=0.45 appx
at t=3: w = exp(1.35) + 1
w = 5 lbs appx
2007-04-20 08:24:49 · answer #1 · answered by cattbarf 7 · 0⤊ 0⤋
About 37% growth rate about 5.2 pounds.
2007-04-20 15:17:44 · answer #2 · answered by sparkles 6 · 0⤊ 1⤋
i think you need to rephrase the question...you said that the puppy's weight increases proportionally to its weight. did you mean age?
2007-04-20 15:15:52 · answer #3 · answered by freddie freeloader 3 · 0⤊ 2⤋